Bill Cassidy, the freshman senator from Louisiana and a doctor, has been pushing fellow Republicans in his first few months in the Senate to embrace an alternative to Obamacare — one he predicts will insure more people without mandates.

And he even says he has a way to pay for it: Obamacare. At an event attended Monday by fellow GOP freshmen to mark the fifth anniversary of the Affordable Care Act, Cassidy took an unusual tack for a Republican by bemoaning the fact that 30 million people remain uninsured, despite the ACA.

He also took aim at the law for leaving pregnancy as “a pre-existing condition.” Asked about that assertion in a hallway interview the following day, Cassidy noted that uninsured pregnant women are only eligible to sign up for Affordable Care Act exchange plans during open enrollment or once their baby is born.

“Now if a woman is pregnant, she’s not signed up, she’s not covered until she delivers. She doesn’t get prenatal care! She doesn’t get prenatal care! … Now, is that a good thing? No. But that’s what they left," he said.

More broadly, Cassidy, who noted he treated uninsured people for decades as a doctor in a public hospital, said Obamacare uses a combination of penalties, mandates and “bribes” to get people to submit to the administration’s will.

“It’s actually in our nation’s interest for people to have insurance,” but there should be a voluntary approach, Cassidy said.

He told CQ Roll Call his plan could cover those pregnant women, and many more, by providing tax credits large enough for people to afford major medical insurance and giving states the ability to auto-enroll people in insurance plans unless they opt out.

“That is not a mandate. It is not a penalty, but it is a way, behavioral economics teaches, that will get most people enrolled,” he said.

He predicted his approach would insure more people than the Affordable Care Act has.

“If you had a system where states could auto-enroll, I think you’d be there. You’re always going to have Theodore Kaczynski, who you don’t know exists, under some hood in Montana.”

Women who get pregnant while being uninsured could have a rolling auto-enrollment period, Cassidy suggested.

"Somebody who is homeless has now come to the emergency room, didn’t know she had coverage, but we can, in a rolling enrollment, put her in for at least a baseline of coverage," he said.

There could be restrictions on plans purchased mid-year to prevent gaming the system. But even with restrictions, items such as prenatal care could be covered.

The tax credits would be at least equal to the tax breaks people get for having employer-sponsored health insurance, Cassidy wrote in a column that ran in The Hill in February.

Asked how he would pay for such a bill, Cassidy cited the taxes that finance the president’s health care law and pointed to the upcoming Supreme Court case over the legality of subsidies in states that did not set up their own health exchanges.

“King v. Burwell obviously affects only a small scope of Obamacare, and one of the things it does not affect are the revenue streams. So, one thing you can do is basically take those revenue streams and distribute them in a way which is frankly a better plan. It doesn’t have the coercion or the bribes or the penalties or the mandates.”

Getting rid of the mandates has broad appeal, he said.

“I was with a bunch of college students last night. I said, ‘Everyone raise your hand if you want people telling you what to do?’ Nobody raised their hand."

Of course, the administration and insurers have long contended that without the mandates, the ban on pre-existing conditions would lead to sharply higher premiums as the sickest people get insurance and healthier, younger people opt out.

There's another big issue with Cassidy’s suggestion of using Obamacare revenue to pay for the Obamacare replacement — the House and Senate GOP budget blueprints. The GOP budget on the Senate floor uses the revenue from Obamacare to reduce the deficit, while nuking the spending in the law on subsidies and the like.

Without the Obamacare revenue, the GOP's 10 year budget blueprint wouldn’t come close to eliminating the deficit in the targeted tenth year.

Cassidy predicted Republicans ultimately will get a price tag from the Congressional Budget Office for a replacement plan.